The San Antonio Film Festival opens Monday with the premiere of a new docudrama that explores San Antonio's Spanish roots.

Three years in the making, “Texas Before the Alamo” begins with the history of Spanish soldiers and Franciscan priests in establishing the city's missions, and extends to the work of Alamo conservationist Adina de Zavala.

A 15-member delegation from the northern Mexican state of Coahuila, led by Guerrero Mayor Francisco García Castells, will be in San Antonio to attend the opening. The free outdoor screening will begin at 7:15 p.m. at HemisFair Park.

The two-hour film, in which several Texas historians and Mexican descendants of Spanish soldiers appear, is part of a six-hour, three-part miniseries that its filmmaker Bill Millet hopes to air on Texas PBS stations.

KEDT in Corpus Christi and KMBH in Harlingen already have agreed to air it, he said.

The project was filmed at historic sites in South Texas and Coahuila and was produced in Spanish with English subtitles. Acting scenes were improvised with the help of historians on site during filming, Millet said.

In part, the film project grew out of a concern that Texas history begins and ends with the Battle of the Alamo in 1836.

“Texas Before the Alamo” details the Spanish mission system's reach into present-day Texas, specifically how the Alamo started off as Misión San Francisco Solano in Coahuila in 1700. That mission was transferred to San Antonio as Misión San Antonio de Valero from 1718 until 1793, he said.

Later still, it was renamed the Alamo by Mexican and Tejano soldier-settlers.

“The Texas missions are Mexican missions,” Millet said. “They were made with a cookie-cutter design by the same designers, the same contractors, the same everything.”

Millet said he hopes the film inspires viewers to learn a wider breadth of Texas history.